In Horizon there are non-street legal cars such as the Ferrari 599XX and the Maserati MC12 Versione Corse. In real life, you could be arrested for driving these cars on open roads, but not in Horizon. One could argue that the ones in the game were heavily modified to make them road-legal note a few people in real life have also converted cars such as the FXX or P1 GTR into street-legal vehicles .
The fact there is no police presence is even more questionable: the radio DJs allude to street racers being picked up by the cops, yet nothing like that is ever seen.
Cars don't have license plates in Horizon and Horizon 2. Word of God says that as the car manufacturers are supplying the cars to the Horizon Festival (which is true, as radio chatter confirms this), this means the player is effectively buying them for pure competition/race use, meaning they're not meant to be on the road and thus, don't need plates. Still odd though: then why you're perfectly able to drive through the open roads? A non-issue from 3 onward, as you can tack your own custom plate to the back of your cars.
There's an abandoned Quattro in Horizon 4 with a siren. And Bullet Holes. Alex, rather disturbed, locks the garage you find it in after pulling it out.
